!  File: codata.h
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! -- Fundamental constants, atomic units, Avogadro's constant
!
!  Revised 2006/06/24 with 2002 CODATA recommended values.
!  From
!    Reviews of Modern Physics 77, 1-107 (2005)
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!
!  codata.h revised 1999/04/29 and combined with units.h
!
!  From
!  "CODATA Recommended Values of the Fundamental Physical Constants: 1998"
!                     Peter J. Mohr and Barry N. Taylor
!  Journal of Physical and Chemical Reference Data, Vol. 28, No. 6, 1999
!
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      REAL*8 XAMU, XAU
      REAL*8 XTANG,XFAMU,ECHARGE,HBAR,XFMOL
      REAL*8 CVEL, ALPHAC, ALPHA2
      REAL*8 FPEPS0
      REAL*8 XTJ,XTKAYS,XTHZ,XTEV,XKJMOL,XKCMOL,XTKJML
      REAL*8 XTKCML,XTNM,XAJOUL,XTANGM10,XPRTMAS
      REAL*8 XFSEC,XTKMML,TESLA,AUTK,DEBYE,DIPSI,PMASS,EMASS,CCM
!
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#ifndef CODATA1998
!
!  Codata 2002
!
      PARAMETER ( XAMU     = 9.1093826D-31, XAU = 1.66053886D-27 )
      PARAMETER ( XFAMU    = XAU / XAMU )
!X  new value corresponds to 1822.8884796D0 (ie no change with 10 sig fig)
!Xold PARAMETER ( XFAMU    = 1822.88848D0 )
      PARAMETER ( XTANG    = 0.5291772108D0 )
      PARAMETER ( XTANGM10 = XTANG*1.0D-10 )
      PARAMETER ( ECHARGE  = 1.60217653D-19 )
      PARAMETER ( HBAR     = 1.05457168D-34 )
      PARAMETER ( XFMOL    = 6.0221415D23 )
      PARAMETER ( PMASS    = 1.00727646688D0 )
      PARAMETER ( EMASS    = 9.1093826D-31 )
      PARAMETER ( AUTK     = 3.1577465D5 )
      PARAMETER ( XTKMML   = 974.864D0 )
      PARAMETER ( XPRTMAS  = 1836.15267261D0 )
#else
!
!  Codata 1998
!
      PARAMETER ( XTANG   = 0.5291772083D0, XFAMU  = 1822.88848D0,      &
             ECHARGE = 1.602176462D-19, HBAR  = 1.054571596D-34 )
      PARAMETER ( XFMOL   = 6.02214199D23 )
      PARAMETER ( XTANGM10= XTANG*1.0D-10 )
!
      PARAMETER ( PMASS   = 1.007276470D0,   EMASS = 9.10938188D-31 )
      PARAMETER ( XTKMML  = 974.864D0 )
      PARAMETER ( AUTK    = 3.1577465D5 )
      PARAMETER ( XPRTMAS = 1836.1526675D0 )
#endif
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!
!     Fine structure constant
!
      PARAMETER ( CCM     = 299792458.0D0)
      PARAMETER ( CVEL    = CCM*XTANGM10*EMASS/(HBAR))
      PARAMETER ( ALPHAC  = 1.0D0/CVEL,     ALPHA2 = ALPHAC*ALPHAC)
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#include <pi.h>
! -- 4*pi*epsilon0
      PARAMETER ( FPEPS0 = 1.0D7/(CCM**2) )
! -- conversion from hartree (au) to:
      PARAMETER ( XTJ     = HBAR**2/(XTANGM10*XTANGM10*EMASS),          &
     &       XTHZ    = HBAR/(2.0D0*PI*XTANGM10*XTANGM10*EMASS),         &
     &       XTKAYS  = 1.0D-2*XTHZ/CCM,                                 &
     &       XTEV    = XTJ/ECHARGE,                                     &
     &       XKJMOL  = XTJ*XFMOL*1.D-3,XKCMOL = XKJMOL/4.184D0,         &
     &       XTKJML  = XKJMOL,         XTKCML = XKCMOL,                 &
     &       XTNM    = 1.0D7/XTKAYS,   XAJOUL = 1.0D18*XTJ)
!
! -- other
!
      PARAMETER ( XFSEC   = HBAR/XTJ)
      PARAMETER ( TESLA   = (XTANG*XTANG*ECHARGE/HBAR)*1.D-20 )
      PARAMETER ( DEBYE   = ECHARGE*XTANG*CCM*1.0D11 )
      PARAMETER ( DIPSI   = ECHARGE*XTANGM10*1.0D+30 )
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! --- end of codata.h ---
